Dasysyrphus laticaudus (Curran)

Locke, Michelle M. & Skevington, Jeffrey H., 2013, Revision of Nearctic <i> Dasysyrphus </ i> Enderlein (Diptera: Syrphidae), Zootaxa 3660 (1), pp. 1-80 : 39-42

Dasysyrphus laticaudus (Curran)

Figures: 8A–E, 20C

Synonyms and References:

Syrphus laticaudus Curran 1925: 175 , Pl. XI Fig. 151 (original description)

Metasyrphus laticaudus :

Fluke 1933: 117 (key, redescription and transfer to Metasyrphus )

Dasysyrphus laticaudus :

Stone et al. 1965: 563 (catalogue and transfer to Dasysyrphus )

Vockeroth 1986: 203 (synonymized under pauxillus )

Vockeroth 1992: 68 (key and redescription)

Diagnosis: Maculae oblique and fairly uniform in thickness. Like D. pauxillus , D. pacificus and D. nigricornis , maculae on tergites 3&4 do not reach edge of abdominal margin ( Figs 8A, B & D ). Dasysyrphus laticaudus differs from the other three in that the markings on tergite 2 in the female extend anterolaterally to the edge of the abdomen ( Fig. 8B ) and in the male they extend similarly, sometimes only slightly, but usually do not reach the edge ( Fig. 8D ). Maculae on tergites 3&4 usually come very close to the margin, if not narrowly touching it, but never crossing it ( Figs 8A, B & D ).

Redescription:

Body Length: 5.0– 8.2mm; Wing Length: 4.8–7.8mm

Head: Frons dark with light pollenose fascia (in males it runs along ventral edge of where eyes meet, in females it is ⅓–½ the length between the antennae and ocelli with a separation medially and edges triangular to rounded) and dark pile, some females with light pile; face light with dark vitta ¼–⅓ the width of the face, usually coming close but not reaching antennal socket, face with dark pile lateral to the eye, shorter in females; gena dark with light to dark pile; occiput dark, covered in light pollen, pile light; scape and pedicel light to dark, flagellomere usually dark with light base.

Thorax: Scutum dark, may appear shiny or metallic, pile variable, from all light to variable to all dark; scutellum light to dark with darker lateral edges, pile on female mostly light with some dark, male typically with dark pile, but sometimes with some light pile anteriorly; wings densely microtrichose, some with small bare areas in br above the base of the spurious vein ( Fig. 8E ); haltere light; profemur ¼–⅓ dark basially, ⅔–¾ light apically, mesofemur ⅓–½ dark basially, ½–⅔ light apically in males, pro-and mseofemora of females are light, base may be slightly darkened ( Fig. 8B ), metafemur ⅔–¾ dark basially, ¼–⅓ light apically, tibiae light, metatibia with dark band ¼ of the way from the apex, sometimes extending to apex, tarsii light, sometimes dark anteriorly.

Abdomen: Maculae on tergite 2 large and oval, in female the anterolateral edge reaching the edge of the tergite ( Fig. 8B ), in males there is a small projection but it terminates before the edge ( Fig. 8D ), maculae on tergites 3&4 are oblique fairly straight and of uniform thickness, maculae do not reach abdominal margin ( Figs 8A, B & D ); sternites light with dark fasciae of varying thickness.

Male Genitalia: Surstylus more or less triangular in lateral view, flattened posteriorly, long pile on dorsal, laterodorsal and posterodorsal sides, row of spines on posteromedial edge; cercus oval with long pile over entire surface; gonostylus boot-shaped but slightly more narrow apically than basally, with projection on posterodorsal surface, projecting dorsally, pile on dorsal surface; basiphallus elongate, basally bent at a slightly more than 90 degree angle towards dorsum, apical end curved ventrally, but does not greatly extend ventrally and is partly membranous dorsally, with spines on posterodorsal side; distiphallus elongate, apical end flared out into horn, which is mostly sclerotized but membranous at apex, with no setulae dorsally, basally bent towards dorsum and usually greatly enlarged at bend with a triangular projection, projecting ventrally ( Fig. 8C ). Extremely similar to D. pauxillus ( Fig. 14D ).

Intraspecific Variation: Female maculae on tergite 2 tend to be similar across individuals, however on males, the extent of projection on the anterolateral edge can vary. Male femora are always dark basally and light apically. Many females have predominantly light femora (especially the profemur; Fig. 8B ). Females from the northwestern part of the range (Yukon) have femora that are dark basally and light apically. Wing cells are usually densely microtrichose, but sometimes have very small bare areas in cell br, above the spurious vein. Basal horn of distiphallus occasionally has few minute setulae dorsally.

Etymology: Comes from the Latin words latus, meaning broad and cauda, meaning tail.

Distribution: Eastern and northern Canada (MB, NB, NT, NS, NU, ON, QC, YK) and northeastern and northern USA (AK, CT, ME, MA, MI, NH, NY). ( Fig. 20C )

Ecology: Collected from April–July, but more commonly in June and July. Collected at elevations of 792– 1067m. Habitats this species has been collected from, according to label data, are “Mh/Be forest” (mixed hardwood/beech), “hardwood forest”, “mixed forest”, “pine forest”, “coniferous woods”, “at top of limestone bluff” and “top of open S-facing bluff”. It has been recorded as being collected on pine trees ( Pinus Linnaeus ; Pinaceae ).

Discussion: Dasysyrphus laticaudus is hereby resurrected from synonymy with Dasysyrphus pauxillus (synonymized by Vockeroth (1986)). Vockeroth (1986) considered them to be the same species, presumably with only slight morphological differences between the species being mistaken for intraspecific variation. Dasysyrphus laticaudus is very similar to pauxillus ( Figs 14A & B ) and pacificus ( Figs 13A & B ), with the later two being extremely difficult to distinguish from each other. There are however, morphological and genetic characters that distinguish laticaudus from pauxillus and pacificus . Their distributions are also predictable and largely nonoverlapping.

Type Material: “Orillia Ont/ 5.v.1921 ”, “Collector/ H. Curran”, red label “ HoloTYPE / Syrphus / laticaudus/ CNC No. 497 Curr.”, “CNC Diptera / #15382”; ♂, deposited in the Canadian Collection of Insects , Arachnids and Nematodes ( CNC), Ottawa, ON. (examined)

Material Examined:

Paratypes: Canada: Ontario: SIMCOE CO.: Orillia, [44.609505, -79.42068], 4.v.1921, ♀, CNCD 13851, 5.v.1921, ♂, CNCD 13885, H. Curran ( CNC). Other Material Examined: Canada: Manitoba: Winnipeg, [49.88333333, -97.13333333], 20.vii.1948, ♂, JBWM 206845, W.H. Fell, 24.v.1949, ♀, JBWM 206517, C.F. Barrett ( JBWM). New Brunswick: CHARLOTTE CO., [45.23102, -66.925304], 9.vi.1955, ♀, CNCD 13909, W. T.A. Neilson ( CNC). YORK CO.: Fredericton, [45.959225, -66.640351], 3.v.1913, ♂, CNCD 13900, 5.vi.1958, ♂, CNCD 13901, ( CNC). Sackville, [45.998, -64.3591], 7.v.2010, ♂, JK 969, J. Klymko, S.L. Robinson, D.M.Mazerolle ( NBMB). KENT CO.: Kouchibouguac National Park, [46.819201, -64.96788], 19.v.1977, ♂, JSS 18365, 26.v.1977, ♀, CNCD 13908, W.P. Hanley, 20.v.1977, ♂, CNCD 13897, 24.v.1977, ♂, CNCD 13898, ♀, CNCD 13907, B. E. Cooper, 22.v.1977, ♂, CNCD 13899, 2♀, CNCD 13905, 13906, 23.v.1977, ♂, CNCD 106793, Hanley & Cooper, 23.v.1977, ♂, JSS 18364, J.D. Lafontaine ( CNC). Northwest Territories: Wholdaia Lake, [60.680702, -104.293128], 2.vii.–4.vii.1966, ♀, CNCD 13779, J.G. Chillcott ( CNC). 21 miles east Tuktoyaktuk, [69.426844, -132.172475], 20.vi.1971 – 25.vi.1971, ♀, CNCD 13773, D.M. Wood ( CNC). Nova Scotia: INVERNESS CO., Cape Breton Highlands National Park, Pleasant Bay, [46.822961, -60.799065], 9.vi.1984, CNCD 60066, 12.vi.1984, ♀, CNCD 13904, B.E. Cooper ( CNC). Nunavut: Ford Lake, M. T.S. Gravity Survey Camp, [63.133386, -107.416561], 28.vi.1966, 3♂, CNCD 13716–13718, G.E. Shewell ( CNC). Ontario: KAWARTHA LAKES DIV., Fenolon Falls, [44.538149, -78.735433], 27.v.1927, ♀, CNCD 13856, F.P. Ide ( CNC). Chaffeys Locks, [44.56666667, -76.31666667], 15.v.1975, ♂, ROMEnt Spec. No. 115136, J.C.E. Riotte ( ROME). HASTINGS CO., Maynooth, [45.229716, -77.940949], 25.v.1951, ♀, CNCD 13857, J.F. McAlpine, 22.v.1970, 2♂, CNCD 13883, 13884, D.M. Wood, 10.v.1987, CNCD 60346, D. Bell & M. Wood ( CNC). Griffith, 7 miles East, [45.243279, -77.031193], 31.v.1983, ♀, CNCD 13858, B.E. Cooper ( CNC). ALGONQUIN PROVINCIAL PARK: Cranjelly Lake, [45.28719, -78.28012], 7.v.–21.v.2009, JSS 22433, 22435, 21.v.–4.vi.2009, JSS 22436, E. Proctor ( CNC); Madawaska Lake, [45.3261, -78.3056], 12.v.–27.v.2007, 2♂, JSS 20747, 21358, 9.vi.–24.vi.2008, JSS 22430, 24717, 24718, 15.v.–29.v.2009, JSS 22434, 7.vi.–21.vi.2008, JSS 24719, 1.v.–15.v.2009, JSS 22431, E. Proctor ( CNC); Crossbar Lake, [45.32686, -78.29997], 15.v.–29.v.2009, ♂, JSS 24614, 22432, E. Proctor ( CNC); Florence Lake [45.44371, -78.49012], 13.v.–29.v.2007, ♂, JSS 21353, 19.v.–3.vi.2009, JSS 22437, E. Proctor ( CNC); Sitting Duck Lake, [45.44985, -78.46831], 21.v.–21.v.2008, JSS 24643, E. Proctor ( CNC); Cecil Lake, [45.4511, -78.4956], 6.vi.–20.vi.2008, JSS 25250, E. Proctor ( CNC); Pondweed Lake, [45.46488, -78.43066], 6.vi.–19.vi.2008, JSS 23709, 26.v.–9.vi.2009, JSS 22441, 16.v.–28.v.2007, 2♀, JSS 21354, 21355, 9.v.–16.v.2007, 2♂, JSS 21356, 21357, E. Proctor ( CNC); Lake of Two Rivers, [45.57177, -78.46515], 11.v.–25.v.2009, ♂, JSS 24613, 11.v.2009, JSS 22440, 11.v.2009 – 25.v.2009, JSS 22438, 22439, E. Proctor ( CNC); Kearney Lake Campround, [45.57267, -78.439397], 11.vi.2005, ♀, JSS 19761, L. Bartels ( CNC); Lake Sasajewun, [45.58, - 78.36], 19.v.1965, ♂, ROMEnt Spec. No. 115125, S.M. Smith ( ROME); Brewer Lake, [45.58551, -78.31044], 18.v.2009 – 2.vi.2009, JSS 22442, E. Proctor ( CNC); Algonquin Park, 11.vi.2003 – 18.vi.2003, ♂, ROMEnt Spec. No. 98519, ♀, ROMEnt Spec. No. 98518, Mark Vanderwel ( ROME). Ottawa, Stack Road, [45.320852, - 75.736188], 7.v.2007, 6♂, CNCD 30882–30887, J. R. Vockeroth ( CNC). Constance Bay, [45.495933, - 76.08694444], 18.iv.2010, ♂, JSS 19757, J. Skevington ( CNC). COCHRANE DIST,: Low Bush, Lake Abitibi, [48.91608, -80.139852], 7.vi.1925, ♀, CNCD 13852, 9.vi.1925, ♀, CNCD 13853, 14.vi.1925, ♀, CNCD 13854, 16.vi.1925, ♀, CNCD 13855, N.K. Bigelow ( CNC); 9.vi.1923, UASM # 149023, N.K. Bigelow ( UASM); 6.vi.1925, BOC 34683, 7.vi.1925, ♀, BOC 34684, 9.vi.1925, 2♀, BOC 34685, 34686, 13.vi.1925, ♀, BOC 34687, 16.vi.1925, 2♀, BOC 34688, 34689, 24.vi.1925, ♀, BOC 34690, N.K. Bigelow ( ROME); 14.vi.1925, ♀, JSS 21337, 15.vi.1925, ♀, JSS 21338, N.K. Bigelow ( MCZ). Almonte, 18.v.1951, ♂, CNCD 106791, J.F. McAlpine ( CNC). Quebec: OUTAOUAIS: Aylmer, [45.400224, -75.817137], 28.v.1923, 2♀, CNCD 13866, 13867, 29.v.1923, ♀, CNCD 13868, 16.v.1924, 5♂, CNCD 13887–13890, 106792, 2♀, CNCD 13864, 13865, 10.v.1925, ♂, CNCD 13886, C.H. Curran ( CNC); Hull, [45.447639, -75.733192], 26.v.1923, 4♀, CNCD 13859–13862, 24.v.1923, ♀, CNCD 13863, 14.v.1924, 2♂, CNCD 13891, 13892, C.H. Curran ( CNC); 27.v.1923, ♀, BOC 34691, C.H. Curran ( ROME); Beechgrove, [45.64508, -76.123602], 15.v.1951, ♀, CNCD 13874, 3.v.1968, ♂, CNCD 13894, ♀, CNCD 13875, J.F. McAlpine ( CNC); 27.v.1963, ♀, CNCD 13876, 15.v.1961, ♂, CNCD 13895, ♀, CNCD 13877, J. R. Vockeroth ( CNC). VAUDREUIL- SOULANGES: Mount Rigaud, [45.466534, -74.325875], 13.v.2008, ♂, JSS 17647, J. Skevington, J. Gibson, A. Sugarman ( CNC); 1.v.1986, ♂, JSS 18342, B.E. Cooper ( CNC); 10.v.1986, 3♂, JSS 20763–20765, B.E. Cooper ( CNC). Duncan Lake, near Rupert, [45.68138889, -76.05027778], 5.vi.1971, ♀, CNCD 13881, J.F. McAlpine ( CNC). LE CENTRE- DE- LA- MAURICE: Lac Mondor, Near Ste. Flore, [46.625254, - 72.768842], 15.v.1951, ♀, CNCD 13869, 16.v.1951, ♂, CNCD 13893, ♀, CNCD 13870, 21.v.1951, 2♀, CNCD 13871, 13872, E.G. Munroe ( CNC). LA HAUTE- GASPESIE: Mont Albert, [49.131813, -66.464367], 1067m, 1.vii.1954, ♂, CNCD 13896, W.J. Brown ( CNC). Rupert River, [51.483333, -78.766667], 19.vi.1956, ♀, CNCD 13878, J. R. Lonsway ( CNC). SEPT- RIVIERES- CANIAPISCAU: 37 km North West of Schefferville, [55.038335, - 66.424521], 12.vi.1981, ♀, CNCD 13880, F. Brodo ( CNC). Great Whale River, [55.116816, -76.405554], 7.vii.1949, ♀, CNCD 13882, J. R. Vockeroth ( CNC). Yukon Territory: 10 km North of Carcross on Highway 2, [60.2596, -134.749909], 5.vi.1981, ♀, JSS 18373, C.S. Guppy ( CNC). Bluefish Ridge, [67.15, -140.6166667], 792m, 2.vii.1983, 2♀, JSS 20049, 20050, 7.vii.1983, ♀, JSS 20069, R.J. Cannings ( UBCZ). 6 km East of Old Crow, [67.566667, -139.683333], 13.vii.1981, ♀, JSS 18366, C.S. Guppy ( CNC). Old Crow, [67.571219, - 139.833877], 4.vii.1983, JSS 20071, R.A. Cannings ( UBCZ); 13.vii.1981, CNCD 60075, C.S. Guppy ( CNC). Firth River, [69.207056, -140.071033], 22.vi.1984, ♀, JSS 18375, S.G. Cannings ( CNC). United States of America: Alaska: MATANUSKA- SUSITNA COUNTY: Matanuska, [61.541945, -149.229674], 12.vi.1944, ♀, JSS 19515, J. Chamberlin ( CNC). Connecticut: NEW LONDON COUNTY: Lyme, [41.400831, -72.342951], 4.v.1918, ♂, JSS 19491, C. T. Greene ( CNC). Maine: AROOSTOOK COUNTY: Crystal, [45.95953, -68.361018], vi.1980, ♂, CNCD 26441, S.N. Pease ( CNC). Maryland: PRINCE GEORGE' S COUNTY: Laurel, [39.101761, -76.860489], 25.v.1965, ♂, CNCD 26728, ( CNC). Massachusetts: WORCESTER COUNTY: Sunderland, [42.244545, -71.77175], 15.v.1965, ♂, JSS 19492, F.C. Thompson ( CNC). HAMPSHIRE COUNTY: Amherst, [42.34038, -72.496818], 3.v.1963, 4♂, JSS 19493–19496, 7.v.1963, ♂, JSS 19497, 14.v.1963, ♂, JSS 19498, F.C. Thompson ( CNC). Michigan: CRAWFORD CO.: 27.v.1958, ♀, JSS 21151, 21152, R. & K. Dreisbach ( MSUC). New Hampshire: CHESHIRE CO.: Jaffrey, [42.814957, -72.022399], 4.vi.1919, ♀, CNCD 26424, C.W. Johnson ( CNC). Glen House, [44.289163, - 71.225764], 14.vi.1911, ♀, JSS 21339, N.K. Bigelow ( MCZ). Mt. Monadnock, 11.vi.1932, ♀, JSS 23773, A.L. Melander ( USNM). New York: TOMPKINS CO.: Ithaca, [42.444589, -76.499268], 11.v.1898, ♀, CNCD 26425, C.W. Johnson ( CNC); ESSEX CO.: Corlear Bay, Lake Champlain, [44.483961, -73.418207], vi.1939, ♀, JSS 19499, R.C. Shannon ( CNC).

Figures

FIGURE 8. Dasysyrphus laticaudus: A: female (CNCD 13875) dorsal habitus; B: female lateral (CNCD 13875) habitus; C: lateral view of male (CNCD 30087) genitalia; D: male (JSS 20763) lateral habitus; E: wing base (JSS 24614). Dorsal and lateral habitus scale bar = 1mm, genitalia and wing scale bar = 500µm.

FIGURE 13. Dasysyrphus pacificus: A: male (CNCD 35314) dorsal habitus; B: male (CNCD 35314) lateral habitus; C: wing base (CNCD 60058); D: lateral view of male (CNCD 26435) genitalia. Dorsal and lateral habitus scale bar = 1mm, genitalia and wing scale bar = 500µm.

FIGURE 14. Dasysyrphus pauxillus: A: male (JSS 24616) dorsal habitus; B: male (JSS 24616) lateral habitus; C: wing base (CNCD 13830); D: lateral view of male (CNCD 13746) genitalia. Dorsal and lateral habitus scale bar = 1mm, genitalia and wing scale bar = 500µm.

FIGURE 20. Dasysyrphus species range maps (symbols indicate specimen point data). A: D. amalopis (squares) and D. creper (circles); B D. intrudens complex; C: D. laticaudus (circles) and D. richardi (squares); D: D. limatus.